Distribution analysis of airborne nicotine concentrations in hospitality facilities

A number of publications report statistical summaries for environmental tobacco smoke (ETS) concentrations. Despite compelling evidence for the data not being normally distributed, these publications typically report the arithmetic mean and standard deviation of the data, thereby losing important information related to the distribution of values contained in the original data. We were interested in the frequency distributions of reported nicotine concentrations in hospitality environments and subjected available data to distribution analyses. The distribution of experimental indoor airborne nicotine concentration data taken from hospitality facilities worldwide was fit to lognormal, Weibull, exponential, Pearson (Type V), logistic, and loglogistic distribution models. Comparison of goodness of fit (GOF) parameters and indications from the literature verified the selection of a lognormal distribution as the overall best model. When individual data were not reported in the literature, statistical summaries of results were used to model sets of lognormally distributed data that are intended to mimic the original data distribution. Grouping the data into various categories led to 31 frequency distributions that were further interpreted. The median values in nonsmoking environments are about half of the median values in smoking sections. When different continents are compared, Asian, European, and North American median values in restaurants are about a factor of three below levels encountered in other hospitality facilities. On a comparison of nicotine concentrations in North American smoking sections and nonsmoking sections, median values are about one-third of the European levels. The results obtained may be used to address issues related to exposure to ETS in the hospitality sector.     

Patterns of host switching in the fish ectoparasite <Emphasis Type="Italic">Argulus coregoni</Emphasis>

Mating is essential for sexually reproducing species to pass on their genes. For sexual parasites, this implies a need to switch the host in the search for a mate when potential partners are not available on the same host, although host switching includes risks like starvation and predation. Studies of mate-searching behavior predict that commonly only one sex searches for mating partners while the other remains stationary. In the present work, we experimentally infected rainbow trout (Oncorhynchus mykiss) with the fish ectoparasite Argulus coregoni and determined whether the sex, age and the presence of mating partners influenced the host switching activity. Our results show that increased host switching by A. coregoni occurred only after the parasite reached the adult stage and a difference between the sexes was also recorded. Host switching by mature males was enhanced when no mating partners were present on the same host, whereas females remained mainly stationary on their host regardless of male presence or absence. Our data therefore support the hypothesis that there is a strategic difference in reproductive behavior between males and females; males invest energy in mate searching while females are rather stationary and invest into body size and hence increased fecundity. Our data also showed that leaving the host to find a mate is potentially costly in terms of predation since a substantial number of free-swimming parasites were eaten by fish.     

Errors and uncertainties in a gridded carbon dioxide emissions inventory

Emission inventories (EIs) are the fundamental tool to monitor compliance with greenhouse gas (GHG) emissions and emission reduction commitments. Inventory accounting guidelines provide the best practices to help EI compilers across different countries and regions make comparable, national emission estimates regardless of differences in data availability. However, there are a variety of sources of error and uncertainty that originate beyond what the inventory guidelines can define. Spatially explicit EIs, which are a key product for atmospheric modeling applications, are often developed for research purposes and there are no specific guidelines to achieve spatial emission estimates. The errors and uncertainties associated with the spatial estimates are unique to the approaches employed and are often difficult to assess. This study compares the global, high-resolution (1 km), fossil fuel, carbon dioxide (CO₂), gridded EI Open-source Data Inventory for Anthropogenic CO₂ (ODIAC) with the multi-resolution, spatially explicit bottom-up EI geoinformation technologies, spatio-temporal approaches, and full carbon account for improving the accuracy of GHG inventories (GESAPU) over the domain of Poland. By taking full advantage of the data granularity that bottom-up EI offers, this study characterized the potential biases in spatial disaggregation by emission sector (point and non-point emissions) across different scales (national, subnational/regional, and urban policy-relevant scales) and identified the root causes. While two EIs are in agreement in total and sectoral emissions (2.2% for the total emissions), the emission spatial patterns showed large differences (10~100% relative differences at 1 km) especially at the urban-rural transitioning areas (90–100%). We however found that the agreement of emissions over urban areas is surprisingly good compared with the estimates previously reported for US cities. This paper also discusses the use of spatially explicit EIs for climate mitigation applications beyond the common use in atmospheric modeling. We conclude with a discussion of current and future challenges of EIs in support of successful implementation of GHG emission monitoring and mitigation activity under the Paris Climate Agreement from the United Nations Framework Convention on Climate Change (UNFCCC) 21st Conference of the Parties (COP21). We highlight the importance of capacity building for EI development and coordinated research efforts of EI, atmospheric observations, and modeling to overcome the challenges.

     

Worst case scenario study to assess the environmental impact of amine emissions from a CO2 capture plant

Use of amines is one of the leading technologies for post-combustion carbon dioxide capture from gas and coal-fired power plants. This study assesses the potential environmental impact of emissions to air that result from use of monoethanol amine (MEA) as an absorption solvent for the capture of carbon dioxide (CO₂). Depending on operation conditions and installed reduction technology, emissions of MEA to the air due to solvent volatility losses are expected to be in the range of 0.01–0.8 kg/tonne CO₂ captured. Literature data for human and environmental toxicity, together with atmospheric dispersion model calculations, were used to derive maximum tolerable emissions of amines from CO₂ capture. To reflect operating conditions with typical and with elevated emissions, we defined a scenario MEA-LOW, with emissions of 40 t/year MEA and 5 t/year diethyl amine (DEYA), and a scenario MEA-HIGH, with emissions of 80 t/year MEA and 15 t/year DEYA. Maximum MEA deposition fluxes would exceed toxicity limits for aquatic organisms by about a factor of 3–7 depending on the scenario. Due to the formation of nitrosamines and nitramines, the estimated emissions of DEYA are close to or exceed safety limits for drinking water and aquatic ecosystems. The “worst case” scenario approach to determine maximum tolerable emissions of MEA and other amines is in particular useful when both expected environmental loads and the toxic effects are associated with high uncertainties.     

Specialization and interaction strength in a tropical plant-frugivore network differ among forest strata

The degree of interdependence and potential for shared coevolutionary history of frugivorous animals and fleshy-fruited plants are contentious topics. Recently, network analyses revealed that mutualistic relationships between fleshy-fruited plants and frugivores are mostly built upon generalized associations. However, little is known about the determinants of network structure, especially from tropical forests where plants' dependence on animal seed dispersal is particularly high. Here, we present an in-depth analysis of specialization and interaction strength in a plant-frugivore network from a Kenyan rain forest. We recorded fruit removal from 33 plant species in different forest strata (canopy, midstory, understory) and habitats (primary and secondary forest) with a standardized sampling design (3447 interactions in 924 observation hours). We classified the 88 frugivore species into guilds according to dietary specialization (14 obligate, 28 partial, 46 opportunistic frugivores) and forest dependence (50 forest species, 38 visitors). Overall, complementary specialization was similar to that in other plant-frugivore networks. However, the plant-frugivore interactions in the canopy stratum were less specialized than in the mid- and understory, whereas primary and secondary forest did not differ. Plant specialization on frugivores decreased with plant height, and obligate and partial frugivores were less specialized than opportunistic frugivores. The overall impact of a frugivore increased with the number of visits and the specialization on specific plants. Moreover, interaction strength of frugivores differed among forest strata. Obligate frugivores foraged in the canopy where fruit resources were abundant, whereas partial and opportunistic frugivores were more common on mid- and understory plants, respectively. We conclude that the vertical stratification of the frugivore community into obligate and opportunistic feeding guilds structures this plant-frugivore network. The canopy stratum comprises stronger links and generalized associations, whereas the lower strata are composed of weaker links and more specialized interactions. Our results suggest that seed-dispersal relationships of plants in lower forest strata are more prone to disruption than those of canopy trees.     

Comparison of two reactor concepts for anoxygenic H2 production by Rhodobacter capsulatus

In the contribution at hand two main concepts of photobioreactors are considered: the flat-panel reactor and the tubular reactor. Both reactors are investigated under outdoor conditions in Germany in the summer time for their applicability for H₂ production by means of purple non-sulphur bacteria Rhodobacter capsulatus. The experiments are performed as fed batch. The performance of a photobioreactor is evaluated in terms of H₂ productivity per IRS (illuminated reactor surface). It is demonstrated that both reactors could be operated stable for several weeks with comparable H₂ productivities. The mean hydrogen productivity for the panel and the tubular reactor is 3690 ml H₂/(m_IRS² d) and 3350 ml H₂/(m_IRS² d) respectively. While approximately 8 m² of the illuminated reactor surface of the panel reactor can be installed on 1 m² of ground space, the relation of the illuminated reactor surface to the ground area for the tubular reactor is approximately 1–1.     

Non-specific association between filamentous bacteria and fungus-growing ants

Fungus-growing ants and their fungal cultivar form a highly evolved mutualism that is negatively affected by the specialized parasitic fungus Escovopsis. Filamentous Pseudonocardia bacteria occurring on the cuticle of attine ants have been proposed to form a mutualistic interaction with these ants in which they are vertically transmitted (i.e. from parent to offspring colonies). Given a strictly vertical transmission of Pseudonocardia, the evolutionary theory predicts a reduced genetic variability of symbionts among ant lineages. The aim of this study was to verify whether actinomycetes, which occur on Acromyrmex octospinosus leaf-cutting ants, meet this expectation by comparing their genotypic variability with restriction fragment length polymorphisms. Multiple actinomycete strains could be isolated from both individual ant workers and colonies (one to seven strains per colony). The colony specificity of actinomycete communities was high: Only 15% of all strains were isolated from more than one colony, and just 5% were present in both populations investigated. Partial sequencing of 16S ribosomal deoxyribonucleic acid of two of the isolated strains assigned both of them to the genus Streptomyces. Actinomycetes could also be isolated from workers of the two non-attine ant species Myrmica rugulosa and Lasius flavus. Sixty-two percent of the strains derived from attine ants and 80% of the strains isolated from non-attine ants inhibited the growth of Escovopsis. Our data suggest that the association between attine ants and their actinomycete symbionts is less specific then previously thought. Soil-dwelling actinomycetes may have been dynamically recruited from the environment (horizontal transmission), probably reflecting an adaptation to a diverse community of microbial pathogens.     

A fast one-pot synthesize of crystalline anglesite by hydrothermal synthesis for environmental assessment on pure phase

Environmental Science and Pollution Research - Anglesite (PbSO4) is a lead sulfate that belongs to the barite group and is naturally ubiquitous in the environment. This work describes a simple way...     

Announcing the 2022 Arnold Berliner Award Winner: spider research at the International Space Station

The Science of Nature - Migration is used by many species as a strategy to deal with a seasonally changing environment. For some species, migration patterns can vary across different or even within...     

The impacts of warfare and armed conflict on land systems

ABSTRACT

Land-use decisions can change abruptly in response to shocks, and warfare and armed conflicts are among the most drastic and globally frequent shocks. Yet, our understanding of where armed conflict affects land systems, how land-use patterns are impacted, and how far-reaching and persistent these changes are, is partial. We used a spatially detailed dataset on armed conflict and a literature review to explore these questions. A number of key insights emerged from our study: (1) warfare and armed conflict affect land systems mainly in more densely populated areas, regardless of the dominating land use; (2) warfare and armed conflict can impact land systems in major ways, but these effects are diverse and not unidirectional; (3) warfare and armed conflict primarily affects land systems locally, but can forge telecouplings; and (4) although the impact of warfare and armed conflict is often immediate, it can instigate long-lasting land-use legacies.